Process for rendering materials water-repellent



Patented Mar. 1944 PROCESS FOR RENDERING MATERIALS WATEB-BEPELLENT Adalbert Miiller, Augsburg, Germany: vested in the Alien Property Custodian No Drawing. Application May 3, 1940, Serial No.

9 Glaims.

For rendering materials water-repellent and waterproof, there are used aqueous emulsions of paramn, waxes, resins and soaps f polyvalent metals, together with aluminum salts.- The emulsions contain protective colloids and emulsifiers,

such as gelatine, glue and other albumins, or sulphonation products of aromatic and aliphatic hydrocarbons. All these compounds serve to stabilize the emulsions, i. e., to maintain the emulsified substances in the finely dispersed state. However, the are not necessary for obtaining the water-repellent efiect; on th contrary, they may even impair that efiect. There is also the danger of re-emulsliication when cleaning the impregnated materials.

The emulsions and the aluminum salts are either used in two baths, or the aluminum salts are added to the diluted emulsions. An improvement was obtained by proposing to combine all substances in a ,concentrated emulsion which, after being diluted, served to prepare the treating bath.

The degree of the impregnating eiiect inter alia depends on the quantity of aluminum salts used. However, large quantities of aluminum salts are difiicult to incorporate in commercial emulsions containing protective colloids, because the viscosity of the solution of the protective colloid or of the emulsion increases very greatly, a great force or high temperatures being required for continuously mixing. On the other hand, by a high temperature the most frequently used protective colloids are decomposed, hardened or impaired. The stability of the obtained emulsions has sufiered Or the emulsions are difilcillt to dilute.

All these dificulties may be avoided if for rendering materials water-repellent there are used aqueous emulsions which contain no protective colloidsbut, practically, only the impregnating substances, viz. aluminum salts or salts of tetravalent metals and fatty substances. The quantity of the aluminum salts used in such emulsions may vary within wide limits, according to the desired effect. 7

Furthermore, the emulsions have the advan= tage of much lesser changing of the feel of the materials treated therewith than those containing protective colloids, while at the same time producing generally equal and often even better impregnating eflects. Especially the waterproofness is considerably increased according to pressure tests by Schoppers method.

The absence of a protective colloid also avoids April 2, 1940 that the treated fabrics are subjected to the risk of mould and damp-stain formation.

.In addition, the emulsions used according .to the present invention may be readily diluted with water, whereas the commercial emulsions containing protective colloids often have to be melted before the can be diluted, as gelatine or glue, which are most commonly used as protective colloids for such purposes, will jellify when becoming cool.

Finally, impregnations with emulsions according to the present invention will to a great extent often stand laundering or dry cleaning.

In preparing the emulsions it is, of course. necessary to adapt the properties of the fatty subt stances andof the aluminum salts to one an-' other. The aluminum salts or the salts of tetravalent metals must be basic, i. e., they must obntain less than the equivalent quantity of acid, whereas the fatty substances should have a low acid value of about 10 to 25; otherwise it is necessary to add fatty acids, their alkaline soaps, alkaline salts of soap-like, capillary-active substances or their free acids in quantltiesof about 10% or less of the weight of the fatty substances. This may be effected by addition to the fatty substance or also to the metal salt solution, but should in any case precede the emulsification. Suitable fatty acids are especially such with 16 or more carbon atoms. They may also b unsaturated or they may contain oxy-groups. Erremples of soap-dike, capillary-active substances are compounds such as sulphonated oils, fats or fatty alcohols, aliphatic, aromatic or hydroaro- 1 matic sulphonic acids, condensation products of fatty acids with oxyor aminoethane sulphonic acid or their derivatives or homologues, 'or with albumin cleavage products. By fatty substances there are to be understood saponiflable waxes, fats oils and resins, as

well as fatty alcohols, parafiin hydrocarbons or mineral oils or soaps 0f polyvalent metals. The

at a lower temperature. As solvents there are preferably used chlorinated hydrocarbons, such as canbon tetrachloric, trichlorethylene, chlorbenzol, but also many other solvents, such as benzol, benzene, tetralene or diethylene-dioxide are suitable.

Various preparing methods are described in applicant's copending patent application, Serial No. 327,344, filed April 1, 1940, on Aqueous emulsions and process for their production."

The emulsions according to the present invention are throughout oil-in-water emulsions with an acid reaction, containing in excess basic salts of aluminum and tetravalent metals. The proportions of all the fatty substances and the metal salts, expressed as aluminum oxide, are such that to one part of the latter there may be about /2 to 7 .parts of the fatty substances. The quantities of fatty acids, soaps or soap-like, capillaryactive substances, as far as at all present, amount to about 10% or less of the weight of the fatty substances.

The aluminum salts and the salts of tetravalent metals may both be present. Highly suitable examples of the latter are zirconium, thorium, uranium and titanium.

Furthermore, salts, acids or dressing agents may subsequently be added to the emulsions or to the diluted treating baths if special effects are desired.

Advantageously, the treating baths are prepared from concentrated emulsions which are diluted with multiples of their own weight of water. Apart from lower costs of transportation and production, the concentrated emulsions also have the advantage that the proportions of the salt and fatty substances may fluctuate within considerably wider limits which also makes it possible to obtain a better adaptation of the composition to the desired impregnating effect.

The procedure can be usefully employed in treating textiles, paper, skins, leather, and like porous materials which are advantageously rendered water-repellent and waterproof.

The impregnating methods are those which are customarily applied with aqueous emulsions. Drying may also be effected in the usual manner.

The following examples are to illustrate the process without, however, limiting its scope.

Example 1.-An emulsion prepared by intimately mixlng 30 kgs. of a solution of basic aluminum formate (22% A120: and 31% of formic acid) and 60 litres of hot water on the one hand and a melted mixture of 20 kgs. of paraffin, l kgs. of parafiin oil, and 3 kgs. of oleic acid, on the other hand, is diluted with warm water in the proportion of 1 to 25 and placed in a lizser or a padding machine. Gabardine cloth consisting of wool or of wool and rayon staple fibre is treated therewith by repeated passage at a temperature of 30 to 40 C., squeezed out and dried. It possesses verygood water-repellent properties and also a good waterproofness.

Example 2.4 kgs. of an emulsion containing 5.7% A1203, 6.3% .of formic acid and 14.3% of hard wax (melting point 70 0., acid value 19), and prepared by intimately mixing the melted wax with a solution of basic aluminum formate, are diluted with 100 litres of warm water. Mantle cloth is treated on a jigger or a padding machine by repeated passage at 30 C. and then finished as usual.

The cloth may also be impregnated, after dyeing and rinsing, on a washing machine with 5% II as they are necessary assume of the above emulsion, calculated on the weight of the article. The article runs for an hour through such a bath, whereupon it is dried and finished. In this way too, there is obtained a 5 very good water-repellent and waterproof impregnation. If for the bath there is used water of a higher content of impurity by way of temporary hardness or an alkaline reacting water. a preliminary addition of a small quantity of acetic or formic acid is of advantage in order to avoid the flocculation of the highly diluted emulsion. The effect may be still more increased by adding to the emulsion, for example, 2% of crystallized zirconium oxychloride or thorium nitrate and a corresponding quantity of sodium acetate in order to neutralize the mineral acid.

Example 3.Wool yarn or mixed yarn of wool and rayon staple fibre is impregnated on the vat or in a yarn dyeing apparatus with a bath prepared by diluting 2 kgs. of an emulsion containing of wax and 6% of zirconium oxide in the form of the basic acetate with 100 litres of water. The impregnation is effected at to 40 C. after the dyeing. The emulsion may be 25 prepared by emulsifying a wax having an acid value of 20 with a solution of basic zirconium ace- 'tate. Example 4.--A concentrated emulsion is prepared by emulsifying a solution of 6.5 kgs. of 30 paraffin in 1.5 litres of carbon tetrachloride with 80 litres of an aqueous solution of basic aluminum formate (8% A1203) which also contains 0.3 kg. of sodium salt of tetralene-sulphonic acid. A 2% to 4% dilution of this emulsion may be used for impregnating paper and is, for this purpose, sprayed on the paper sheet by means of a suitable device. Thereupon the paper sheet is dried and then possesses water-repellent properties and an increased tearing quality so that it is suitable as packing material. 9

The impregnation may also be effected in the beater engine by adding the emulsion to the paper pulp.

A 2% dilution of the emulsion may also be used for producing impregnated paper yarn, in which case the solution serves for moistening and damping the paper band before the cutting- The strip! which are still wet are wound into yarn in the spinning machine and subsequently dried.

Example 5.-Together with the water-repellent impregnation, textiles may also be subjected to other treating operations; for example rendering crease-resistant. For this purpose, an emulsion is used which is prepared by emulsifying kgs. of hard wax (acid value 12) 25 litres of paraffin oil, and 30 litres of carbon tetrachloride or another chlorinated hydrocarbon on the one hand, and 210 kgs. of an aqueous solution of basic aluminum formate and zirconium formate (19% A1101, 2.5% ZrOa, and 25% of formic acid) on the other hand, and subsequently stirring in of '70 litres of warm water. 6 kgs. of this emulsion, 1 kg. of urea and 2 litres of formalin are dissolved in litres of water. Addition is suitably made of 300 gs. of tartaric acid. Then a rayon plush i treated by passing it twice on the sizing machine at 40 C. Thereupon the plush is brushed, dried on the tenter at 70 C. and subsequently subjected for 10 minutes to a heating of about C. It possesses very good water-repellent and to a large extent crease-resistant properties.

Example 6.The impregnating may be combined simultaneously with filling operations, such with canvas and tents fabrics. There is used a bath containing 8% of the emulsion according to the present invention and, furthermore, 2% of glue, 3% of dextrine and 2% of an aluminum formate solution of 12 B. The goods are placed into the bath in the dry state and passed twice on the padding machine at 50-60 0.; they are subsequently dried as usual.

The emulsion used for the bath may be prepared by emulsifying a mixture of paraffin, paraffin oil, copper oleate and trichlorethylene with an aqueous solution of a basic aluminum formate and the sodium salt of an alkylated naphthalene sulphonic acid, and contains 16% paraflin, 8% of paramn oil, 1.6% of copper oleate, 24% trichlorethylene, 10% aluminum oxide and 2% of the sulphonic acid salt. The copper oleate serves as preserving agent for the glue and the dextrine.

Example 7.Leather may be impregnated by lubricating it as usual in the fulling trough with a train-oil emulsion, then continuing the fulling for about an hour with 5% of an emulsion according to the present invention (calculated on the weight of the leather) and the required quantity of water, and then finishing as customarily. Such an emulsion contains, for example, 7.3% of A1203, 12.0% of paraifin, 4.5% of parafiin .oil, 1.2% of stearic acid, and 14.1% of trlchlorethylene, and is prepared by intimately mixing paraflin,

paraifin oil, fatty acid, and solvent on the one hand, with an aqueous solution of basic aluminum formate; on the other hand.

Example 8.--For impregnating skins, it is advantageous to use undiluted emulsions and to spread them thereon, whereupon the skins are dried on the ironing machine, roughened up, and sheared. If required, the treatment is repeated in order to increase the effect. Finally, the skins are beaten. A suitable emulsion is, for example, one that is prepared by emulsifying 24.5 parts by weight of a mixture of paraffin and parafiln oil, to which are added 10% of oleic acid, with 72 parts by weight of a solution of basic aluminum formate, containing 7.3% A1203 and 10.1% of formic acid. There may also be added to the emulsion organic solvents for more rapidly wetting the skins, as well as glazing agents, such as are customarily in use in preparing furs, as for example adipic acid esters.

Example 9.-13 kgs. of resin are allowed to swell up for some hours in the equal quantity of perchlorethylene, dissolved by heating and mixed with 64 kgs. of melted paramn. Thereupon the mass is intimately mixed at 50-60 C. with 120 kgs. of a basic aluminum formate solution (22% A1203, 31% of formic acid), which contains 3 kgs. of an un-rieutralized sulphonated oil. Finally, 52 litres of warm water are added.

A bath, containing 1% of this emulsion, may be used for impregnating acetate rayon yarn on a cheese dyeing apparatus. The yarn which is dyed and rinsed, is hydroextracted and treated with the bath on the apparatus for 30-40 minutes at 40 C., then again hydroextracted and dried. It may be used for the manufacture of umbrella silk.

The treatment on the yarn dyeing apparatus involves a further advantage of the emulsions according to the present invention in that they are much less foaming than emulsions containing protective colloids, such as glue.

What is claimed is:

1. Process for rendering porous materials water-repellent and waterproof which comprises treating the same with a stable aqueous emulsion consisting of a. continuous phase comprising water and a. water-soluble basic salt of a polyvalent element selected from a group consisting of aluminum, zirconium, thorium, ura- 5 nium and titanium, and of a disperse phase comprising particles including a water-insoluble organic impregnating substance of an acid number between 10 and 25 selected from the group 7 consisting of waxes, fats, oils, resins, 10 fatty alcohols and higher aliphatic hydrocarbons, said basic salt being effective for maintaining the emulsion stable in the presence of the said organic substance of low acid number and in the substantial absence of a protective colloid.

2. Process for rendering porous materials water-repellent and waterproof which comprises treating the same with a stable aqueous emul sion consisting of a continuous phase comprising water and a water-soluble basic salt of a 2 polyvalent element selected from a group consisting of aluminum, zirconium, thorium, uranium and titanium, and of a disperse phase comprising particles including a water-insoluble organic impregnating substance of an acid number between and selected from the group consisting of waxes, fats, oils, resins, fatty alcohols and higher aliphatic hydrocarbons, said disperse phase also comprising an emulsifier selected from a group consisting of higher fatty oils, acids, alkaline salts or such acids, sulphonated oils and hydrocarbons, and salts and alkyl esters of such sulphonated compounds, the proportion of the emulsifier being less than ten percent of the quantity of said water-insoluble organic substance, said basic salt being effective for maintaining the emulsion stable in the presence of the said organic substance of low acid number and in the substantial absence of a protective colloid.

, 3. A process as in claim 1, in which the waterlnsoluble organic impregnating substance in the disperse phase is present in the form of a solution in a halogenated hydrocarbon, the solvent being present substantially in the quantity of 50 to 100 percent of the total weight of the said substance. I

4. A process as in claim 1, in which the watersoluble basic salt is a salt of a water-soluble lower aliphatic acid.

5. Process for rendering porous materials water-repellent and waterproof which comprises treating the same with a stable aqueous emulsion consisting of a continuous phase comprising water and a water-soluble basic aluminum salt and a water-soluble basic zirconium salt, and of a disperse phase comprising particles including a water-insoluble wax of acid number between substantially 10 and 25, said basic salts being effective for maintaining the emulsion stable in the presence of the said organic substance of low acid number and in the substantial absence of a protective colloid.

6. Process for rendering porous materials water-repellent and waterproof which comprises treating the same with a stable aqueous emulsion consisting of a continuous phase comprising water and a water-soluble basic aluminum salt of an organic acid, and of a disperse phase comprising a water-insoluble wax of low acid number and a higher aliphatic hydrocarbon, said basic salt being effective for maintaining the emulsion stable in the presence of the said organic substance of low acidnumber and in the substantial absence of a protective colloid.

7. A process as in claim 6, in which the wax and hydrocarbon are present in the form of a solution in a volatile organic solvent.

8. Process for rendering porous materials water-repellent and waterproof which comprises treating the same with a stable aqueous emulsion consisting of a continuous phase comprising water and a water-soluble basic aluminum salt of an organic acid, and of a disperse phase comprising a water-insoluble higher aliphatic hydrocarbon, said disperse phase also comprising an emulsifier selected from a group consisting of higher fatty oils, acids, alkaline salts or such acids, sulphonated oils and hydrocarbons, and salts and alkyl esters of such sulphonated compounds, the proportion of the emulsifier being less than 10 percent of the quantity of said hydrocarbon, said basic salt being effective for maintaining the emulsion stable in the presence the emulsion stable in the presence of the said organic substance of low acid number and in the substantial absence of a protective colloid.

ADALBERT MUIIER. 

